shift linkage adjustment, first gen (no Lo)

Hello all,

My 64 never has gone into Lo very well: the car needs to be at a full stop, and even then, it can be iffy. (I've read here that one should be able to downshift at anything under 40 mph?) Recently there was a period of not going into lo at all--annoying for me, since I live on the top of a very steep hill and it helps w/the braking.

OK, so, to take a look at things, and maybe fix some leaking fluid along the way (new cork pan gasket, flattened bolt hole in the pan, new manual shift seal), I got the pan off and have been messing around. What I found was that with the shift lever in Lo, I'm only getting half-way to the Lo setting on the detent lever:

So, seeing only one place to make an adjustment, I went over to where the shift rod bolts to the linkage, loosened the adjuster nut, and... I can't get any more adjustment out of the thing. Detent lever still in same place.

Any ideas much appreciated! I want to start burning sub $3 gas ASAP...

nick

Check for wear on the linkage rods and the holes in the frame where the linkage fits. I used some Mr. Gasket bushing for a four speed shifter to firm up some sloppy linkage in my '63. Those bushings are still available from JEGS or Summit Racing.

Ed

OK, Ed, interesting: well, there's certainly some play in the linkage, and I may just want to replace those bushings. But I just found out that when I remove the linkage arm going to the manual shaft on the trans, I can't manually slide the detent lever past the point in the photo. The problem? the manual valve (as the manual calls it) is hitting against the crenelated nut that seems to hold down the solenoid. The end of the manual valve is the bright cylinder in the below photo.

I don't get it. Unless somehow when I took out the manual shaft to replace the seal, I somehow reinstalled the lever in the wrong position. In that case, one might surmise that the manual shaft is currently at its proper maximum position (meaning Lo), and that what's wrong is that the lever is off a bit. However, it was my impression that the lever only goes on one way--one can't get it "off a tooth" like a timing chain or sth. I don't know, maybe not. Anyone have a sense of where the manual valve sits when in Lo?

Hmm... I should have observed this better BEFORE changing the shaft seal. A common occurrence with me, it seems.

Hmm... I should have observed this better BEFORE changing the shaft seal. A common occurrence with me, it seems.

A cheap digital camera in the tool box is probably worth 5X what it cost. I learned that in the SoHK (School of Hard Knocks)

heh, yeah. But then I still would have had to have had the brains to go through all the positions by hand to check them out.

Looking at pictures of the lever, I can't possibly see how I could get the reassembly "off" by some amount. That's out , I think.

However, looking at the trusty manual, on p 5-128 it says: "Note: Be sure the manual valve is properly indexed with the pin on the manual detent lever." I have a feeling that the pin on the lever is not supposed to simply "push" the valve (as it does in my first photo of the OP), but that the valve has a kind of groove and the pin must be in the groove so that it'll have a push-pull function. (The way it's set up in the photo, moving the trans linkage can only push the manual valve in.) It looks that way in the manual pix--tho the things are microscopic. That would explain why the valve's currently bottoming out--if the pin were lined up right, the valve would never go that far. Ah ha!

Well, I'm going to reinstall the lever tomorrow and see where I'm at. Knew I shouldn't have bothered with that shaft seal!

yesterday's hypothesis confirmed: I created my own problem. Well, at least I've been able to verify that the linkage is now adjusted correctly for the correct range.

Also, thanks Ed for your tip on some thread about flattening out the pan edge around the bolt holes--mine had definitely been overtorqued at some point. Now everything's snug at 12 ft lbs.

Soon I'll do those bushings to make the linkage nice and tight. Currently, a couple of them are bad--esp the one that goes into the frame.

Since I last posted to this thread, I was looking through my bins for a couple of screws and came across the top of the package of the Mr. Gasket shifter bushings that I had used on my '63 some 20 years ago. I ran the part number through Summit Racing an lo and behold, it's still a good part #. Here's a link that will get you there.

http://www.summitracing.com/parts/mrg-11

Ed

Nice, thanks Ed. On a related transmission issue, maybe you could help. I removed the vacuum modulator to change the o-ring. The manual clearly shows the modulator valve sticking out from the tranny. I didn't see it, however, when I removed the VM. Is it simply stuck inside the modulator body? I see something in there moving... but it doesn't want to come out. Also, am I right to think that when handling the VM fluid shouldn't come out of the vacuum port? (Seemed to me that some may have dripped out--the way I understand it, that would mean a bad diaphragm. Otherwise, though, the trans had been working fine part my problem getting in Lo (and the leaks).)

nick

Nice, thanks Ed. On a related transmission issue, maybe you could help. I removed the vacuum modulator to change the o-ring. The manual clearly shows the modulator valve sticking out from the tranny. I didn't see it, however, when I removed the VM. Is it simply stuck inside the modulator body? I see something in there moving... but it doesn't want to come out. Also, am I right to think that when handling the VM fluid shouldn't come out of the vacuum port? (Seemed to me that some may have dripped out--the way I understand it, that would mean a bad diaphragm. Otherwise, though, the trans had been working fine part my problem getting in Lo (and the leaks).)

nick

You are correct on both counts

Tom

OK, good to know, thanks Tom. I'm going to have to replace the VM, then, because fluid is definitely coming out the port. But how do I get the valve out of the VM? Magnet didn't work; I tried jiggling with a screwdriver a bit. Assuming the vale does not come as part of the new modulator.

Just a report back, FYI.

The linkage kit Ed suggested didn't seem to be right: contained metal bushings that were a little loose on the linkages and that (for that mounting at least) won't fit into the hole in the frame. Instead, I got these bushings:

http://www.summitracing.com/parts/ATP-FO405

You need to drill them out to 3/8" (basically the I.D., but there's some strange lip in there as well), as well as prune their width with an Xacto, since the stock ones are much thinner and you can't get the hairpins through otherwise. But the fit is perfect, linkage nice and tight. 4 of them does it.

For the vacuum modulator, since CARS was showing in their picture the exact replica of the original, I ordered that rather than going for the other replacement that everyone has for the TH400. Naturally, CARS sent me what everyone else had, at twice the price. Anyway, that's in there now, with no obvious effect (must have been a small leak). I still don't quite get why the manual shows the vacuum valve as a separate part, whereas in both the old VM and the new, it appears to be part of the assembly. Whatever.

So, I recalibrated the shifter by making sure that when it was in lo, the manual shift selector down at the tranny was in low. And the result is: I can shift to lo at will, including at low speeds. Should have done that 15 years ago.

And: now that I flattened the transmission pan bolt hols (as above), replaced the rubber gasket with a reinforced cork one (rockauto), replaced the manual shaft seal, and the seals on the speedo gear housing, It's pretty dry under there. a little drip from what's probably the front seal, I can (and will) live with that.

Success! Thanks for the help ROAers!

nick

Thanks for the update. I'll keep these in mind if I need something for my '64. When I used the ones I referenced, it was for my '63. Probably a difference in years.

Glad to hear you can now "live with it."

Ed